Many of these are still used by the inhabitants of the valley.
The most visible part of the system are the spiraling, funnel-shaped holes called ojos.
At the bottom they are about a meter or two across.
The wells also let wind into the canals and force the water through the system.
These trenches or aqueducts are V-shaped, and often lined with pebbles to prevent the soil from collapsing.
Many of the open trenches empty into small reservoirs which serve as wells and as distribution points.
But there is no evidence from Spanish texts to support that.
But there is no historical evidence to support that either.
The aqueducts maybe as old as 3,000 years or as recent as 1,250 years.
